A Graduated Aiming Circle for Manual Antenna Aiming in Field Operations

During field operations, the antennas are often turned manually.  In the past, I have had success by placing an aiming circle around the mast as shown below at E6M:


In the photo above, a pointer was made from a large paper clip and taped to the mast.  On recent 6m EME DXpeditions, I have used an M2 Portable Mast, which has a 6" x 6" base plate with a 3" diameter lower mast section.   In order to provide an aiming circle that will fit over the base plate and its anchor pins, I decided to design something that could be made as large as desired.  The concept is shown below:

The original graphic is available at http://www.bigskyspaces.com/w7gj/AimingCircle.gif , and a document including the graphic is available at http://www.bigskyspaces.com/w7gj/AimingCircle.pdf .  As explained on the document page, if blown up 50% in size, it will result iin an inside diameter of 9", which is large enough to fit over even the 6" x 6" base plate I currently use.  The idea is to enlarge the graphic as you want, and cut out a hole in the center of the paper that is larger than your mast (shown below by the orange arrow).  The center of the paper is found by marking a line along a ruler lined up across the 90 and 270 degree marks and one with the ruler lined up along the 0 and 180 degree marks.  Then a compass is used to mark the cutout circle, and the paper is trimmed out to make an empty space in the center where the lamination will seal.  Then trim the edges of the paper, so you can seal it on all sides with a standard 8.5x11" lamination as shown in the photo below. 

The corners of the lamination are left intact, to provide places for holes made by a paper punch  (yellow arrows) so  the aiming circle can be secured in place to the ground with pins (nails, tent pegs, etc.).   Finally, mark the center of the aiming circle with a compass as before, and then draw the diameter of the mast you will be using (red arrow above).   In the example above, I marked the lamination for a 3.0625" circle, to fit closely over the M2 Portable Mast, which is 3.0" diameter at the bottom.   Finally, the hole for the mast is trimmed out using a razor knife to provide clearance to fit over the mast before it is installed on the base plate. 

A pointer can be made from stiff wire taped to the mast; I usually bend a paper clip and tape it to the mast to make a pointer.  Just make sure that the center of your pointer lines up with the center of the mast.  The portable aiming circle above is very lightweight and thin, and can be transported easily along with a laptop computer, in a logbook, or in the bottom of a suitcase.  Happy DXing!

Page last revised on 3 July, 2013